Mailjax – Email Address Validator

From the Gospel according to Paul Maden

The second tool ready for the launch of my Web Developer Tools Site is Mailjax, an Email Address Validator.

A common problem many web developers have to contend with is that of collecting and validating email addresses submitted from web page forms.

My new email validator “Mailjax” is designed to assist the site visitor in entering a valid email address in the first place, making use of fancy new Web 2.0 features to actually validate the email address as visitor types it, displaying a visual indicator as to whether the address is valid.

Part one of the Mailjax tests is to see if the address looks sensible, i.e. does it look like ‘’ rather than ‘Bob’ or ‘’. You wouldn’t believe how many people enter web site addresses when asked for their email! The test is performed by comparing the address against an Email Regular Expression (Regex).

If and only if the address looks sensible, part two is tested, checking to see if the domain name part of the address (everything after the ‘@’ symbol) refers to a domain that is able to receive mail. This is known as checking the MX Record for the domain. If the domain doesn’t exist, or hasn’t got an MX record, then it is not possible to be a valid email address.

Mailjax is still under development, but don’t let this stop you from using it now. Check it out… Mailjax – Email Address Validator, I’d love to receive any feedback, good or bad.